In nearly every modern passenger vehicle, an airbag module is accommodated in the hub region of the steering wheel, which features a housing, an inflator connected to the housing, usually in the form of a gas generator, and an airbag folded into the housing. The steering wheel body herein usually features a receptacle with a bottom and a side, inner wall. In the design known as the “floating module;” the housing is connected to the steering wheel body by means of compression springs, so that it can be pressed down against the force of these springs to operate the horn. To position the housing in the axial direction and to hold the housing against the steering wheel body in the case of an impact, frequently several, and generally three, axial positioning units are provided, which act between housing and steering wheel body and which hold the module against the steering wheel body even during a vehicle impact.
The housing generally consists mostly of plastic, however, due to the large forces occurring during an impact, as a rule it is not possible to manufacture the axial positioning units entirely from plastic. In this regard the generic document DE 10 2010 023 180 A1 proposes a steering wheel unit whose housing features a metal base plate and a housing side wall consisting of plastic. O-shaped lashings joined together with the metal base plate which also forms the bottom of the housing, extend as a single piece downward in the direction of the bottom of the receptacle for the airbag module. These lashings are covered in sections by plastic coverings which extend away from the housing side wall. This forms axial positioning elements on the module side, and hooks extending from the steering wheel body engage into each one. Each of these module-side axial positioning elements features a support unit (the lashing) consisting of metal, and a plastic element covering this support unit in sections.
The disadvantage of the above-described prior art is that the unit is relatively large and thus heavy and difficult to produce, and a flexible bending part of metal is needed for the housing bottom with the molded on lashings.
Proceeding from the problem described above, an object of the present invention is to improve a steering wheel unit of the kind described above, such that the airbag module can be produced with a reduced expense and a reduced weight.
This problem is solved by a steering wheel unit, an airbag module for use in one such steering wheel and, a steering wheel unit for use in one such steering wheel unit as are described by this specification and shown in the accompanying Figures.